With their mouse whiskers, felt ears and pink noses, the crew of "It Ain't Easy Being Cheesy" knew how to work a theme.

But it wasn't until they were paddling across Six Flags Hurricane Harbor's vast wave pool in their yellow chunk of cheese that they wondered if their vessel would actually stay afloat.

"We were worried that it would sink but it didn't," said a clearly relieved Isabel Villarreal, as she and her classmates at Fort Worth's Kirkpatrick Middle School hauled their soggy boat from the water. "I want to do it again."

The first-time participants at the annual Cardboard Boat Regatta were one of a record number of school entries this year. More than 150 boats overall took part in the event, which requires that participants design, build and navigate boats made entirely out of corrugated cardboard.

Hosted by the River Legacy Foundation, the fundraiser grows into a bigger spectacle each year, with boats becoming more ornate and the energy getting more infectious.

Teams dress up in costumes to match their vessel's theme. A few schools even brought along their mascot and drum line.

Organizers said that families, groups and schools have taken ownership of the event because it's a good team-building exercise and a practical application of math, science and engineering. Some teams attend a boat-building camp in February and take months to build their creations while others invest only a few weeks.

"Some do it for the fun, others for the competition," said Kristi Payne, marketing coordinator for the River Legacy Foundation. "It's become a signature event for the community. It's amazing what people can make out of cardboard."

This year's event featured boats of all themes, from ladybugs to crayons, piranhas to pirates. The Bates Container entry, which was awarded Best in Show, featured a realistic stagecoach attached to a team of horses.

Organizers said that while schools throughout the area have gravitated toward the event, after-school groups in particular have found that boat-building is an ideal bonding opportunity for students.

Longtime sponsor Gary Daley, owner of Randol Mill Pharmacy, said the event "brings the whole community together."

"I'm just so tickled to see the school groups out here," he said. "That will be the key to keeping this going."

Daley, who sponsors some youth entries and also builds his own boat, said he and his friend, James Gilmartin, like to compete each year.

"The fun part is coming up with the design and letting our imaginations run amok," Daley said.

Gilmartin, who regularly wins speed records at the event with his creations, built the sleek pontoon structure called "Sudden Rush" with a bicycle top and pedals that push the craft through the water.

He offered this advice to next year's boat builders: "Don't puncture your cardboard, test your boat out in water first and definitely know how to paddle."

For a list of the 2012 winners visit the River Legacy Foundation website.